NEW YORK - The United States, Canada and Mexico should establish a common security perimeter to guard against terrorism in North America, a tri-national independent task force said in a report released on Tuesday.

The countries should police their borders together to help border trade, allow easier movement of citizens and to keep out potential security threats, the task force said at New York's Council on Foreign Relations.

"If our two borders, the one between Canada and the United States and the U.S. and Mexico, became a frontline for security the impact that would have on normal relations and economic relations would be profound," said co-chairman John Manley, a former Canadian deputy prime minister and minister of finance.

The task force was sponsored by private groups in each of the three countries including the U.S. Council on Foreign Relations, and there was no indication that governments would act on the proposals.

The report, titled "Building a North American Community," also called for free movement within the continent for citizens through a North American Border Pass with biometric identifiers and other measures to increase economic and military cooperation between the countries.

William Weld, a former Republican governor of Massachusetts, and Pedro Aspe, former finance minister of Mexico, were the other co-chairmen of the task force, comprised of over 20 experts from government, business and academia.

Manley contrasted the scrutiny of goods flowing between Canada and the United States with a lax attitude to imports arriving at shipping ports.

"As I told my one-time U.S. counterpart (U.S. Homeland Security chief) Tom Ridge once, 'You inspect a grain car entering the U.S. from Saskatchewan closer than you do container traffic coming into the United States from the Middle East.' And I think that's still the case."

Other recommendations included improving labor mobility, developing an energy strategy with greater emphasis on reducing harmful emissions and establishing an investment fund to build infrastructure to connect Mexico's poorer regions in the South to the market of the North.